118 
THE PERIODICAL CICADA. 
ticularly the variation in the structure of the pecuUar comb-Uke 
organ which is found on the apical margin of the front femora, together 
with the important differences in the hairy covering of the body and 
legs. 
TECHXICAL DESCRIPTIOX OF THE DIFFEREXT STAGES. 
F'hst larval stage. — The newly hatched larva (fig. 47, a) is about 1.8 
mm. long from tip of head to the extremity of the abdomen, is rather 
slender and of a nearly uniform thickness throughout, presenting, 
however, the general characteristics of the later larval stages. The 
body is clothed ^^dth numerous 
scattering long hairs. The gen- 
eral color is cream}' wliite, with 
prominent, deep red, almost black, 
eye spots. The antennae, beak, 
and legs are, relativeh^ with other 
stages, very large in comparison 
\\ith the size of the body. The 
anterior legs are developed in 
general as in the later stages, 
though lacking the femoral 
comb-like organ wliich begins in 
the second stage and the minute 
second subapical tooth on the tibia 
which appears in the fourth stage. 
The anterior tibias are also 
more slender and the mandible- 
like tip is more sharply pomted. 
The row of stiff hairs for retain- 
ing the earth excavated in bur- 
romng, so prominent in the 
later stages, is but sparsely rep- 
resented. The anterior tarsus 
is inserted considerably within 
the tip of the tibia, projecting beyond the latter, and is armed 
at its extremity with two nearly ec[ual, curved claws, similar to 
those on the middle and hind tarsi. The basal joint of the two- 
jointed tarsi ill all the feet is very minute and with difliculty detected, 
and in fact becomes still more inconspicuous in later larval develo]> 
ment. The antennae are seven-jointed, as in all the subsec^uent larval 
and i)upal stages (one of the characters distinguishing tliis species 
from other allied species, particularly C. tlhicen, which has an addi- 
tional joint); but the presence of a very prominent antenna! tubercle 
gives an appearance of eight joints, the number which I have liitherto 
assigned to it. The fu'st true joint is robust and a little shorter than 
Fig. 47.— First larval stage: a, newlj' hatched 
larva; h, antenna of same; c, larva eighteen 
months old; d, enlarged anterior leg of same. 
(Author's illustration.) 
